Automatic stabilizing or controlling means for aircraft



G. AvELlNI-. AUTOMATIC STABILIZING 0R CONTROLLINI MEANS FORAIRCKRAFT.

APPLICATION FILED 1AN.I7I920 Patented May 31 ,'1921. 7 SHEETS-SIVIEET I.

. /V/ w? nl//x/ Il? y G. AvELlNE.' AUTOMATIC STABILIZING 0R CONTROLLING MEANS FOR AIRCRAFT.

APPLICATION flLED IAN. I7. 1920.

'tented 'May 3T, T521.

' wwwa 7 SHEETS-SHEET 2- G. AvELlNl-i. AUTOMATIC STA'BILIZING OR CONTROLLING MEANS FOR AIRCRAFT.

APPLICATION FILEDTAN. 17. l1920. v A l ,379,895 Patente May 31, Z

. l '6. AVELINE. AUTOMATIC sTAB|L|z|NG 0R CONTROLLIING AAEAN'asA FOB APPLICATION FILED JAN. I?. 1920.

' l Patented .May '31, 1921.

TSHEETS-SHEET 4. l

AIRCRAFT.

I e. AVELINE. AUTOMATIC sTAluzING 0R coNT'AoLLING MEANS FOR AIRCRAFT-I APPLICATION FILED JAN.17. 1920./ n

7 sHEETssHEET 5. i v

G. AVELINEf AUTOMATIC STABILIZING 0R CONTROLLING MEANS FOR AIRCRAFT.

APPLICATION FILED JAN. I7. 1920.`

G. AVELINE. AUTOMATIC STABILIZING 0R CONTROLLING MEANS FR AIRCRAFIT.

" APPLICATION FILED IAN. I7. 1920.

1,379,895e PaIemeaMAy-sl', 1921.

' M 7SHEETS-SHEEI` 7.

MOND ROZEEERKINS, DECEASED.

GEORGES AvELINE, OE s'oHo, LONDON, ENGLAND, AssIGNOR TO RAYMOND RozE- PERKINS, vOE HENsINGTON, LONDON, ENGLAND; HENRY rAGET-coOHE AND EDITH ANNIE HAMILTON DOUGLAS-HAMILTON EXEOUTORSOE SAID RAY- AAUTOMATIC: sTADILIzI-NG OR cONTRoLLING MEANS -EOR AIRCRAFT.

Application led January i7, 1920. SeriLNO. 352,187.

i To all whom t may concern:

Be-it known that I, GEORGES AVELINE, a

vcitizen of the 'French Republic, residing at .40 `Frith street, Soho, in the county of-London, England, have .invented certain new and useful Improvements in or Relatmg to Automatic Stabilizing or Controllingv is a specification.

This invention relates to automatic st'abilizingorcontrolling apparatus for use on aircraft particularlyl aeroplanes and has general reference to the kind of apparatus in which a gravity influenced member for ex-4 ample a mass of mercury is provided for the Means'for Aircraft, of which lthe following purpose of enabling relative movement be-v tween it and its support or container to take place under certain conditions during flight as for instance when the aircraft angularly moves in order to establish electrical, cir?.

cuits for operating means which actuate a contrivance vconnected to and adapted to move the aircraft controls.

According to this invention the improved stabilizing o r controlling apparatus which comprises a gravity influenced member such as a mercury column in a tube or container for electrically operatingmeans which' actua'tes a contrivance connected to and adapted to move the aircraft controls is so constructed and arranged that after the contrivance has been actuated to move the controls to .right the aircraft or restore it to its normal flying position as a result of the relative displacement b'etween the mercury and its con- .tainerv and the consequent operation of the electrical means, the said electrical means A are again operated on or by the righting movement of the aircraft taking placel in order to effect the reverse movement of the said contrivance thereby positively moving the controls-in the opposite direction so asto restore them'to the normal or required position. A lsemi-circular mercury column is preferably employed and 1s contained 1n a A circular tube in which 'electrical contacts are disposed above the two ends of the mercury column. According to the direction of relative displacement between the mercury .col-

vumn and its container, one` end orV the other of the mercury column establishes electrical circuits for loperatlng electromagnets which control the contrivance con-v nected to the aircraft controls. After Specification of Letters Patent.

t Patented May A31, 1921.

the contrivance has( moved in one di 4rection to move the controls and right the aircraft, it isv automatically moved in the 'opposite direction to restore the controls as the result of energization of electro-magnets controls were-moved to right the aircraft. l

One stabilizing apparatus may be employed for lateral control and a separate apparatus for fore and aft or longitudinal control and in the former case the mercury container is disposed in a transverse plane of the aeroplane` while in the latter case the mercury container isV disposed in the longitudinal plane of the aircraft. In order to insure that the operation of the mercury and its container, can :take place nothwithstanding certain forces or conditions which might in the ordinary way prevent the operation the mercury column is placed under the influence of windI pressure or suction. produced as a resultof the flight of the aircraft pref-' erably by means of suitable Venturi, Badin' a .80

with theirv axes in the direction of flight atV extended positions on the wings one on each side of the body or. fuselage of the aircraft. The Venturi tubes arranged in this manner ,may be so'connected to the mercury conltainer that the two ends of the mercury column are under-the influence ofpressure or suction thus if the mercury tends to bles affected'by centrifugal force when the aircraft.

' banks orI turns, a differential'suction or,l

pressure effect on the ends of the mercury column takes place and counteracts the effect of centrifugal force so that the desired relative movement between the mercury column and its container `can take place. In the `longitudinal plane of the aircraft isl connect-v 'case of fore and aft control the mercury coni -tainer which as stated above is disposed in a ed to a Venturi or similar tube disposed in a neutral position onthe aircraft in' such manner that the two ends of the mercury,

'column are under the influence of difierential pressures say by one end being under the "influence of suction and' the other under pressure. The mercury is therefore nor'- jA mallymaintained by thev suction yeffect inY such a position that a straight line 1drawn i zontal instead of being normally horizontal riations in thesuction `effect due to changes as in the case of lateral control. Thus vain speed or longitudinal angular' movement of the aircraft enable relative movement between the mercury and its container to take place for the purpose aforesaid.' The contrivance which is connected to the aircraft controls may comprise a cylinder containing a double-ended piston geared to a lever con; nected to the aircraft controls,'the piston being adapted to be displaced in the cylinder by air pressure controlled by valves which are electrically controlled as a result of the relative movement which takes place between the mercury and .its container. rlhe extent of movement of the piston and the aircraft controls is dependent upon the amount of relative displacement between the mercury and its container., and the movement of the piston at the end of or during its effective stroke or operation is utilized `to control the electric means and valves in such manner that the return movement of the piston is effected for the purpose of returning the aircraftcontrols and the stabilizing .apparatus .to the normal or Arequired position on the aeroplane being righted.` A pump may be provided for supplying air to the aforesaid cylinder and a main hand controlled valve is also provided which may be operated to render the stabilizingor controlling apparatus operative-or inoperative; the said valve may also be associated with a switch in order that the electrical current placing the apparatus in the operative or,in operative conditions. Various methods of controlling the said electrical means and the air supply maybe utilized, but ineach cas'e the operation of the apparatus is dependent upon therelativeA displacement betweenythe mercury column .and its container. The control of the mercury columns as aforesaid in order to insure of the proper working of the mercury switch taking place under. all conditions is an importantA feature of the invention. The mercury in the transverse position and controlled in the manner aforesaid, provides or vforms an inclinometer or course indicator which will enable the pilot to know when the aeroplane is deviating from the required course. ,One advantage of theinventron is the elimination of rotatingi or gyroscopic mechanism and the ablln thel present incontrol of the aeroplane when desired as it is rendered inoperative so far as its automatic action is concerned, by' actuating the main controlling valvewhich places each end of the aforesaid cylinder in communication with atmosphere so that the piston 1n 'the cylinder is free to move in either direcn tion when the pilot moves the controls.

Generally, a current of about twelve volts is used for operating theaforesaid electromagnets and in order thatthis current is not employed at the contacts in the mercury switch, relay devices may be provided which may be operated by comparatively small currents, say .two volts, vso that the relays when energized complete circuits containing the aforesaid twelve volt electro-magnets. Means may however be employed whereby the operation of the valves controlling the supply of air to the cylinder is effected by the use of small voltage electro-magnets..

ln connection with the apparatus employed for fore and aft control, it may bedesirable to employ a switch device which operates more quickly than the aforesaid mercury switch in order to effect the initial energization of the electro-magnets or the relays controlling the same afterwhich the control is takeny up by the mercury switch. The supplementary and preliminary switch which may be employed may comprise a device operated by wind pressure through a combined `Pitot and static pressure tube; this device may be in the form of an ordinary speed indicator such asoften used on air'- craft. ln some instances for example on small aeroplanes, the piston motor may be substituted by a. motor which comprises gearing actuated by a wind driven fan, the arrangement being such that upon the electrical circuits being completed as a result of the relative displacement `between the mercury andits container, electro-magnets area operated which move the gearing so that one or other of oppositely rotating wheels are vbrought into contact with a wheel which is then rotated to impart rotation in one direction or the other to the shaft connected t0 the air craft controls, according to the direction` of displacement between the mercury and its' container.

lln order that the said invention may be clearly understood and readily "carried into effect, the same will now be described more fu1ly with reference to the accompanying drawlngs, in which Figures 1 and 2 are respectively'an ele vation (partly in section) and a plan of one construction of the contrivance which is connected to and effects the movement of the aeroplane controls.`

Figs. 3 and 4 are transverse sectional views taken respectively on the lines I3--3 and 4-4 of Fig. 1.

Fig. 5 is a diagrammatic view of the geraete t I ing the method of controlling the mercury column in the case of the apparatus being Aused for controlling the aeroplane in the transverse direction.` A

F 1g. 7 1s a diagrammatic view 4illustrating the method of controlling the mercury column in the case of the apparatus 4being utilized for controlling the aeroplane in the longitudinal direction. Fig. 8 is a diagrammatic plan view showing the arrangement of the pipe connections for. theair supply.

Fi 9 is a sectional plan view of the main and controlling valve. Fig. 10 is a diagrammatic plan showin a modified arrangement of thepipe connections for the air supply.

Fig. 11 is a diagram showing theelectrical connections remployed in conjunction with the modification shown'in Fig. 10.

hereinafter explained.

Figs. 14 and 15 are detail. views of parts used in connection with the modification shown inFigs. 12 and 13. n l

Fig. 16 is a diagram of electrical connections showing the relays which are interposed between the mercury switch and the electro-magnets which 'operate the air valves.

Fig. 17is a diagram showing the device for insuring quick action 'of' the apparatus when employed for'fore and aft control.

" Fig. 18 is a detail view of a modification hereinafter referred to.

Figs. 19, 20, 21 and 22 are respectively a plan, a front view, a rear view and an end View of a modification lin which the contrivance connected to the aircraft controls is operated by means of a wind driven fan.

The construction of the contrivance shown in Figs, 1 lto 4 will first be described as the? general features thereof are employed in k the various modifications either when the apparatus is employed for 'controlling the the apparatus is used for the transverse or lateral control 'of the aeroplane or the longitudinal or fore' and aft control thereof.

yReferring particularly to Figs. 1 to4, A`

is the cylinder containing two pistons B B" connected togetherbya rod or bar C so'as. to form a double 4ended piston (hereinafter termed the piston B) the upper part ofthe rodv or bar C is provided wlth a toothed rack C which is in mesh with a pivotedor angularly movable toothed sector D secured to a'spindle E which is mount- 'ed Vin suitable bearings E" (Fig. 3) supported on extensions or uprights A', A on. the cylinder A. Secured to the spindle E is 'a' lever F which is connectedlo either the'. lateral orthe longitudinal controls ac `cording to the use of the apparatus.

The piston B isladapted to be displaced in either diiection in the cylinder by means of air pressure at either end ofthe cylinder, and for the purpose of controlling the air supply an inlet valveY vG and an exhaust valve H are provided atthe left' end of the cylinder, while an inlet valve Gx and an exhaust valve HX are'provided at the right end of the cylinder the arrangement of the sieveral valves being shown more clearly in Figs. 2 and 8. Throughout the specification the index x applied' to the reference letters or numerals indicate parts at the right side of the apparatus which have corresponding parts'at -the left side which are designated by similar reference letters or numerals without the index 111. As indicated in Fig.

1 the said valves may be of the piston type, Figs. 12 and 13 are diagrams of electrif -cal' connections of further modifications and each valve is normally maintained in a definite or normal position relatively to suitable ports in the valve casing by means of springs G', H', GH HX', respectively (see Figs.- 1 and 2. The aforesaid valves are adapted to be operated or moved as or in the order required against the action of the springs as a' result, of the energization of electric coils- G2, H2, G 2,Hx2, which when energized attract pivoted armatures G2113, Gxa, Hconnected to l'the respective piston valves sc as to move the said valves against the action of the' said springs. The ener'- gization ofthe vsaid coils is effected 'by the completion 'of electricalv circuits caused by the engagementof the mercury column K \(see Fig. 6) with suitably disposed contacts in the mercury container K when relative movement takes place between' the mercury`l column and its container, as hereinafter ex:H

plained in describing the operation of the.;` apparatus. Thel inlet and exhaust valves G Q and H are each provided with ftwo ports" G4, G5,H4, H5, respectively- (see Figs. 2I and 8) and the inlet" and vexhaust valves Gx and H are each provided with two ports G, G 5 and H 4 H"5 respectivelyand as shown in Fig. 8 the ports G4 gx? lpertaining to the inlet valves G, 'G" are lconnected by pipes G",`G"6 to the main handlcontrolling ing to the inlet valves G, G* are connected to theres ective end spaces'of cylinder by' ros pipes G7, x7.' The -ports H4, I-IX4 pertaining to the exhaust'valves PLI-I. are "connected,

to therespective end spacesof the cylinder f i HX while the/other` prts 'jH,5',`g12'5 bv pips Hxf also pertainingto the exhaust valves arel open to atmosphere; the two `end spacesv of .l the cylinderare-connected bypipes J,'.J ;.to

the mainvalve'J as shown in Figs. 8 2` 1 1 1d`9.v Normally the k'inlet valvesG, GX. are mainafg, u terence prises an angularly movable cam J see Fig.

9 adapted to coperate'with and control the position or three plungers J3, J, Jt in three branches J 5, J X5, J6 of the main valve casing. Y

The plungers' J3, J 3 arespring pressed against the cam J2 and each controls ports J7, J 7 in its respective branchv so that thev ports J7, J "7 may be closed or placed in communication with the pipes J and J", to place theends of the cylinder in communication with atmosphere through the said ports J7, J". The third plunger J4 controls the supply of compressed air from the main inlet J S connected to a pump (not shown) to the ipes G, GX leading to the inlet valves (in-". When the 'cam J 2 and the twoplungers J 3, J *3 are inl the position shown in Fig. 9, the ports J7, J X7 are open so that the end spaces of the cylinder are opened to atmos' phere while the other plunger J 4 closes the pipes Gr", GX leading to the inlet valves Gr and GX, thus shutting oi the supply of air from the pump. rlhus when the cam J2 is in Athis position the stabilizing apparatus is rendered inoperative as regards lits, automatic control and the electrical current is at this time cut oil' as the ends of the cylinder are at this time openl to atmosphere through the pipes J', J" and the ports J7, J7 so that the piston B vis free to move in either direc tion when the aeroplane' controls (which as aforesaid are connected to the piston B by the lever F) are operated by thek pilot. When it is desired toenable the automatic control to be effected the cam J z is angularly moved through an angle-of by means of the handle J0 see Fig. 8 thus forcing the plungers J3, JX3 outwardl against their springs to close the ports JVJ" and thus close the end spaces of the cylinders; at the same ltime the compressed air through the main inlet J 8 will move the valve against the smaller part of the cam so that the pipes G, Gr 6 are placed in communication with the main air inlet J8 so that the apparatus is then ready for operation assuming the electrical current has been switched on. rlhe electrical switch may be connected to or operated by the handle J0 so that the current is switched o n simultaneously with the opening of the main air inlet J8 from the pump, this operation being readily eiiected bythe aeroplane pilot and the current may bevswitched ofi' simultaneously with the cut,- tin'g oii of the air supply by moving the cam to the position shown in Fig. 9. T he above description generally sets `forthl the construction ot the apparatus which will be iur1 ther described particularly with regard to the electrical connections in setting forth the operation of; the apparatus.

inthe case of controlling the aeroplane in the transverse direction, the contrivance shown in Fig. 1 is arranged in the transverse plane of the aeroplane, and is ernployed in conjunction with the mercury container shown in Fig. 6, the lever F being connected to the lateral controls of the aeroplane, and in .the case of controlling the aeroplane in the longitudinal or fore and aft direction,a contrivance such as shown in Fig. l is arranged in a longitudinal plane of the aeroplane, and is employed in conjunction with the mercury device shown in Fig. 7 the lever Fi in this case being connected to the longitudinal controls of the aeroplane. ln both cases, the general operation of the apparatus is, as aforesaid, caused by reason ot the relative displacement between mercury container K and the mercury column K which resultsin the completion of electric circuits, so as to energize the aforesaid coils G2, H2, GX?, H thus f moving the said inlet and exhaust valves so that' the air pressure may move the piston B and consequentlyv operate the aeroplane contro s.

When the apparatus is employed for controlling the aeroplane in the transverse direction, the container or tube K containing the mercury K is fixed in a vertical or substantially vertical plane transverse of thev aeroplane and in practice it may be secured to the cylinder A as shown in Figs. 1 and 3. As shown in Fig. 5, two series of electric contacts l to l0 and 15 to 10x are provided in the tube or container K on the left and right sides respectively above each end of the mercury column K and are so arranged. that when the container K is angularly displaced due to the aeroplane banking or turning, one series of contacts successively engages With the mercury' column according to the direction of angular movement of the aeroplane. llt is important that the mercury column K should be'mainta-ined at all times .in the position shown in Fig.' 5 and in order to insurethat the mercury column will remain in that position, the-left side of the container K may be connected by means of a pipe K2 to a Venturi, Badin or similar tube K3 at the tip of the wing on the right side of the aeroplane, While the right side of thel container is similarly cross connected by va pipe K 2 to a Venturi or other tube Kx3 at the tip of the wing at the left side of the aeroplane. By means of lthis -cross connection of the container K to the Venturi or similar tubes K3, Kx3 the two ends of the mercury column may be placed under the influence of suction when the aeroplane is flying, and when it is flying level,

ila

cury columnv is balanced or equal. Should the aeroplane bank'or turn to the left', thel action of centrifugal force tends to displace the mercury column to the right, but owing tothe .greater speed of the raised right wing tip in moving in a larger circular path than the depressed left wing tip, the' suction from the Venturi tube K3 to the left-side of the mercury column. will be greater than the suction on vthe right side f thereof, vso that the tendency for the mercury to move from left to right due to the action of centrifugal force is counteracted. A similar action takes place when the aeroplane banks or-turns in the opposite direction, and in this manner the mercury column canbe maintained in a position in which its ends lie in a horizontal plane irrespective of the transverse angular position of the aeroplane. Instead of utilizing the suction effect to control the mercury column, pressure may be used, in which case it would not be necessary to makefthe aforesaid cross connections, as the Venturi or similar tube on the right wing tip would be connected to the right* side of the mercury column,l

and the Venturi tube at Athe left wing tip wouldA be connected to the left side of the mercury column. f

y As shown in Fig. 5 a contact piece 11 is placed in the lower part of the mercury container and it is connected to the positive terminalof-a battery L orother source of `electric supply, so that the mercury column constitutes a conductor which 'isvadapted to f coperate with either series of contacts- 1 to 10 Aor 1X to 10 in the mercury container according to the direction of banking or turning of the aeroplane. The aforesaid sector may carry a'setof contacts 1--10fL on one face connected by'conductors 1* 10b to the set of contacts 1 to 10 on the left side ofthe mercury container and a second set of contacts 1 2 to 10Xa on the other face of the sector is similarly connected to theseries of contacts 1X to 10) on the right lsidel of the mercury container. The contacts 12l to 10a on the sector D are adapted to coperate with two brushes 12 and 13 fixed on the cylinder extensions A., A and connected to the coils G2, H2 by conductors 14 and 15 as shown in Fig. 5, which coils are also connected to the negative terminal of the battery by a conductor 16. In Fig.v 5 the necessary electrical connections are' shown for effecting the controlling operation when the aeroplane turns or banks to the left only, andit will be understood that duplicate corresponding connections (indicated where illustrated by similar reference letters or numerals with the index x) are provided to enablethe controlling operation to be effected when the aeroplane banks o r turns to the right. When the -aeroplane is flying "fthe relative movement between the mercury level,`the ends of the mercury column do not lmake contact with the adjacent series of contacts 1 to'10 or 1x 'to 10x but if'the aeroplane banks or turns tothe left so that its left wing is lower than the right` the con'- tacts 1to 10 will successively plunge into the adjacent end of the mercury column which as statedabove is connected to the battery L. Assuming the main valve has been moved to open the main air inletJf3 75 and to switch on the electrical current a= circuit is immediately established by the contact' 1 on the container K, conductor 1b, contact 1a on-the sector, the two stationary brushes v12 and 13, conductors 14 and 15 the two coils G2 H2 and back to the battery by the conductor 16; the coils G2 H2 thus become energized so as to actuate the armaf .tures G2 H3 which move the" inlet and exhaust valves G H at the left end of the cylinder A against the action of their springs G', H so that the inlet valve G Iopens and the exhaust valve H closes. Immediately the inlet valve G is opened, A air is admitted from the main valve J through the pipe G6 and the pipe G7 to the left end space of the cylinder and lthe piston B is thereby moved to the right and transmits movement by lthe aforesaid toothed rack C to the sector D (and the lever F 95 connected to aeroplane control) thereby causing'the contacts 1a, 2a,fetc., on the sec-- tor to successively engage with the two fixed brushes 12 and 13. The extent of movement depends upon the amount of relative displacement between the mercury column and the contacts 1 to 10. Supposng the angular movement of the aeroplane andl and its container are such that the contacts 1, 2, 3 engage with the mercury and the y contact 4 is not in contact with the mercuy y column the'movement of the piston by t e compressed air will continue until the con-,

Vtact laon'the sector connected with the con- 110 tact 4 in the mercury container K engages with the stationary brush 12 with the result that the current then does not flow through the inlet valve coil G2- which therefore becomes denergized, and allows the inlet valve G to be closed by its spring. The supply of compressed air is therefore cut off and l the movement of the piston 'B and the sector D is stopped. The sector D having been moved, has moved or actuated the aeroplane controls to restore the aeroplane to its horizontal position so that during the restoring or return movement of the aeroplane relative movement between the mercury column K and its container K takes 126 tor in contact with the second stationary brush 13 and thus causes the exhaust valve coil H2 to become denergized so that the exhaust valve ll is opened by reason of its spring H. The armature H3 connected to the exhaust valve is provided with twol contact pieces 17, 17, adapted to engage with two contacts 18, 18 so as to forma switch,-

the aeroplane controls to the normal position.4 The independentcircuit controlled by the opening of each exhaust Valve and the consequent movement of the respective armatures may be effected by a contact 19 on the sector D connected to the positive terminal of the battery L by a conductor 2O this contact 19'being so arranged as to engage with two fixed brushes 21, 21 connected by conductors 22 to the armature switch contacts 17 and 18 which are connected by conductors 23 to the coils Gr) 2 HX2 of the inlet and exhaust valves which coils are connected to the negative terminal of the battery as, shown in `Fig. 5. When the pistonB after being returned has reached its normali'or neutral position shown in Fig. 1

the brushes 21, 21 are out of engagement with the contact 19 and the coils GXZ HX2 are denergized so that the inlet and exhaust valves Gfx, HX at the right end of the vcylinder are restored to their normal positions by their springs, At this time also the'contacts 1 to l0 on' the container K are out of engagement with the mercury andthe various parts are inthe normal position.

lf the aeroplane banks or turns in the opposite direction so that the right wing tip is lower than the left, the contacts 1.X to 10 successively engage with rightiend of lthe mercury column and a similar operation to that abfcve described takes place through the contacts lite 10X and two similar'brushes 12X. andl l3'? and the duplicate connections above mentioned for ena-bling compressed air to be' admitted firstto the right end of the cylinder `by the valve GX which results in -the piston B, the sector D, D and the aeroplane controls being operated so that the aeroplane is restored to its horizontal position and then to the left end of the cylinder to restore the piston B, sector D and the aeroplane controls to the norma-l or neutral position.

When the apparatus. is to be used for stabilizing or controlling the aeroplane in `minimum speed of flight.

:terasse the fore and aft o r longitudinal direction, the cylinder A is as aforesaid arranged in a longitudinal plane ofthe aeroplane and the lever F is connected to the longitudinal controls but thevarious electrical and air supply connctions and the operation are similar to that above described, the operations .K2 K7 leading from above the two ends of the mercury and terminating in asuitable Venturi or other tube K8 disposed at the middle of the wing span, that is in the vertical medial longitudinal'plane of the aero; plane in sucha manner that during the Hight of the aeroplane suction 'actscn the forward end of the mercury through the pipe K. while pressure acts on the rear end of the mercury, through the pipe K7; vthe arrow Y represents the direction of flight of the aeroplane. the pressure and suction on the ends of the mercury vcolumn the latter is maintained in a position with its forward end above and its rear end below the normal horizontal ln this case however, the

@wing to the action -of position as shown by the line Z Z. thus counterbalancing the inertia of the mercury.

The position of the mercury container can be f* controlled by a Ahand lever N.(see F 1g. 3)

within easy reach of the pilot so ythat it can be set to suit any angle' of flight, the pipes K6 K7 being madeflexible or otherwise arranged to permit of the angular movement of 'the container by moving the lever N..

The mercury container`\K4 is provided with two series of contacts connected to two sets of contacts on the sector D which latter are connectedv to the coils G2', H2 GXZ, HXZ as i..

above described. lff for instance the aeroplane loses speed as a result ofengine trouble or stoppage of the engine the pressure and suction effect on the mercury decreases owing to the reduction in speed with the result that the mercury moves from front to rear relatively tothe container and engages with one set of contacts thus establishing an 'electric circuit for energizing thecoils pertaining to the inlet and exhaust Valves at one end of the cylinder to cause air to be admitted to the cylinder and thus effect the movement of the' piston and sector so that the latter operates the controls and causes the aeroplane to dip and increase its speed; l

consequently the, aeroplane can retain a lf however the aeroplane should. dip and increase in speed., the pressure and suction effect would increase and cause the .mercury column to E I move from the rear to the front thus establishing electrical circuit so that the apparatus is actuated to move the aeroplane control which causes the machine to rise or climb thereby'reducing the speed. During normal flight any loss of equilibrium causling variation inthe speedv of the aeroplane will result in a corresponding variation in the pressure and suction effect and displacement of the mercury to enable the automatic stabilizeror controller to be brough into operation. The modification shown in Flgs. 10 and'11 permits of the use of a' pump of less capacity than isrequired in the modification. shown in Figsffl to 9. The main difference consists in so arranging the various'inlet and exhaust valves that each end space of the cylinder isnormally in communication with the air supply, (assuming the lever J0 of the main valve has been adjusted to close the ports J7 Jin) instead ofthe latter being cut ofi when the piston is in its neutral or normal position as in the previous example. For this purpose the various valves maybe arranged as previously explained but the l two previous exhaust valves. (which are normally open) are so connected to the main air supply valveJ and to the cylinder as to serve as inlet valves while the two previous* inlet valves (which are normally closed) now serve as exhaust valves but the valves l occupy the same positions as aforesaid relalin kthe connections being clearly understood 60 byv a comparison of-Fig. 11 and Fig. 5.- The tively to their ports.. The valves which in this case are the inlet valves are lettered G, G* and the valves which in this case are the exhaust valvesare lettered H, Hx and the ,pipe connections to the inlet and exhaust valves and to the cylinders are the same as previously explained as will be understood from Fig. 10; the inlet valves are normally' opened and the exhaust 'valves normally closed so that normally the two end spaces of the cylinder are in communication with the air supply through the pipes G6, Gr"6 and the pressure at both'ends ofthe piston is balanced to maintain it in the neutral or normal position. As will be seen from Fig. 11 the electrical connections are different from the connection shown in Fig. 5 in the respect that the brushes 12 and 13 which coperate with the contacts 1a to 10a on the sector connected to the contacts l to 10 vat the left side of themercury container, are connected respectively to the coil Hxz (pertaining to the exhaust valve HX) and the coil Grx2 v(pertaining tothe inl'et valve'iGrx)l at the right end 0f the cylinder, this Adifference connections from the-contacts 1)c to 10X at theright side of the-mercury container are similarly cross connected tothe coils G2, H2 pertaining to the inlet andl exhaust valves Gr,r H respectively, at the left side of the cyl# inder, these connections however noty being shown .inFign 1'1 as a description of the op eration of the apparatus when the aeroplane turns 'to the left will suiiice for a proper understanding of the invention.

Supposing the aeroplane banks or turns so that its left wing tip is lower than the right wing tip, the engagement of the lcontact 1 with the mercury column will result i Vin the energization *of the coils H, Gr"2 by the circuits above explained. Thus the inlet valve Grx at the right (normally open) will be closed and the exhaust valve Hx (normally closed) will be opened thus opening the right end of the cylinder to atmosphere while the inlet and exhaust valves vGr, H at the left end ofthe cylinder will remain in the normal position c. e., open and closed respectivelyg'thus the air supply being cut olf at the right-end of the vcylinder and this end of the cylinderfbeing open to atmosphere reslllt in a difference inthe fair ,pressureiatr HX2 and thereby causing the closing of the exhaust valve' HX, which in closing lcompletes an independent circuit by 'contacts 17 and 'as aforesaidthereby energizing the coils at the otherend of the,v cylinder so that the inletand exhaust valves at that end respec` tively close andopen, thus opening the right 'end -to atmosphere.. When the -controls have been operated by the piston B the sector D and the 'lever F the aeroplane in returning to its normal 4position xwill cause relative displacement totake place between the mercury andits containerin the opposite direction; as the contact 3 leaves the mercury it will break thel circuit through vthe coil Grx2 with the result that the coil becomesdenergized and thus allows the inlet valve GrX to open by' reason of its spring;v-

' therefore greater pressure of air occurs.-| in the right 'end of the -cylinder so that vthe re-V turn movement of the piston and the' 'aeroplane controls, is effected until the parts reach the normal position'a similar operation takes place when'the aeroplane banks or turns in the; opposite direction." `-With this modification the end spaces of lthe cylinder are normally in communication 'with the compressedair solthat they arev constantly j under pressure thereby differing from the previous examplein which the endsp'aces are normally closed to the air supply and I D for which purpose it is mounted on a' effecting the operation o must be fully charged before the piston can be moved after each return of the piston to its normal position; thus in the first case the air supply is to some extent intermittently controlled. This modification can be used for controlling the aeroplane in the longitudinal or fore and aft direction lby arranging the cylinder A and the mercury container shown in Fig. 7 in a longitudinal plane of the aeroplane.

The modification shown in'Figs. 12 to 14 diners from the two previous examples by the elimination of the series of contacts 1 to 10 or 1X to 10X on the left and right sides of the mercury container and the corresponding contacts on the sector D, the mercury container havin only one contact 1 at the left side and one contact 1x at the right side which contacts l and l are connected by conductors 24, 24X respectively to the coils G2, H2 and the coils G, HW as shown in Fig. 12 (when the intermittent air pressure supply explained in connection with Figs. 5 and Vv8 is used) or the conductors 24 and 24* are respectively connected to thef` coils HX?, GW and the coils H2, G2- as shown in F ig.'12a (when the constant air pressure supply explained in connection with Figs. 10 and 11 is used). rFhe coils are designated iny 12 to agree with those shown in Fig. 5 while the coils shown in Fig. 12a are designated to agree with Fig. 11. ln Figs. l2 and 12 however the complete connections from ythe left -and right sides of the mercury contamer are shown to the corresponding coils whereas in Figs. 5 and 11 only the complete connections from the left side of the mercury container to the respective. coils are shown as previously explained.

In the modification shown in Figs. 12 to 14- the mercury container K is capable of belng angularly moved by the toothed sector spindle M and carries or is secured to a gear wheel M mesh with a toothed quadrant M2 secured or keyed to the spindle E on which the toothed sector D and the control lever F are secured or keyed. Supposing the aeroplane banks or turns-so that its left wing tip is lower than the right wing tip the contact 1 will engage with the mercury thereby establishing circuit and energizing the coils for the piston and the aeroplane controls, by either of the methods Vpreviously explained in connection with the first two modifications; owing to the movement of thepiston to the rightby the air pressure the toothed sector D in being movedv to the right angularly moves thc mercury container by means of the quadrant M2 and the gear wheel M' in the direction of the arrow W, (see Figs. 12 and 14) that is in the opposite direction to the movement oi the container which takes place when the (see Figs. 13 and 14) which is in` neraeee by the toothed sector, lwill cause the contact l to move out of engagement with the mercury so that the coils are denerglzed. rllhe -mercury being maintained with its ends level, the contacts will by reason of the movement of the container assume a level position when they will be out of engagement with the mercury, but the aeroplane at this time will still be in the inclined position; the controls having been operated however as a result of the aforesaid engagementy ot the contact 1 with the mercury cause the aeroplane to commence its righting movement so that the container moves in the opposite direction and brings contact lx at the right side into the mercury thus establishing a circuit which energizes the va/lve coils at the `other end of the cylinder so as to operate the valves and effect the return movement of the piston and the controls. 'lhis return movement of the piston causes the mercury 'container to be angularlymoved in the opposite direction by the quadrant M2 and gear wheel M? until such time that the aeroplane has assumed its normal or level position when the container in being moved by the said gearing moves its contact 1x out of mercury thus breaking the circuit and stopping the return movement. When the aeroplane banks or turns in the opposite direction the contact 1X engages with the mercury thus causing the operation of the piston lP the sector D and the mercury container in the opposite direction.

When the modification shown in Figs. 12 to 14 is utilized for controlling the laeroplane in thev longitudinal direction, the disk 'is capable of angular adjustment at the will of' the pilot by meansof cables N connected llOtl at N to the support carrying the mercury container and passing around pulleys N2, N20, the said support being provided with a curved slot N3 through which extend the by pulling one or other of the cables l according to the direction of angular adjustmentrequired. Generally, a current ot about twelve volts is required for operating the aforesaid electro-magnetic coils. lit may be desirable not. to employ a current of so high a voltage at the contacts in the mercury tube or container qwing to sparking which may take place as the mercury leaves the contacts; therefore relays F, P* may be used (see Fig. 16) which are connected to the contacts 1 1x of the mercury tubeK by conductors lP, FX, the relays also being connected by a conductor F2 to one of the two volt cells of the battery lL in order that a two volt current Hows through the relays 'i engages with the contact 1 or 1X; thus the low voltage current prevents sparking at the contacts 1, 1X in the mercury container.

The relays control by means of their armatures P3, P3X the circuits containing the elec-I tromagnets G2, G2", H2, H22 pertaining to the valves controlling the air pressure to the aforesaid cylinder A, the operation bef'v ing such thatwhen one relay say P is operated as a result of relative displacement between the mercury and its container so that the contact 1 entersthe mercury, the armature'P2 of this -relay is attracted and completes the circuits which contain the electromagnets that operate the valves for al1,

lowing the piston in the cylinder to be operated and theaircraft controls moved in the manner above described. `The return movement of the aircraft controls `is .effect ed as above explained in connection with the modification shown 'in Figs. 12 to 15.

Electric'lamps P2, P2M-:may be connected :across the conductors P and P2 leading from the relays so that immediately rela# tive movement takes-place between the mercury and its containerand a circuit is established through either one .or other of the relays, the corresponding lamp is lighted,

these 'lamps being conveniently placed'onv the instrument board of the aircraft, and

1 thus" forming an indicator or inclinometer to show the angular position of the aircraft. Hv`-In this case all the valves are normally closed and the arrangement is such that when a relay-'is operated a-valveat one end of the cylinder A is vopened and a valve at the other end closed so thatdifvferential air pressure,` at the two ends of the piston takes place and causes movement of the latter as required. When the other relay is operated a similar loperation in the reverse direction takes place.

-In order to render the mercury switch u for fore and aft control sensitive to slightest changes in speed, lan arrangement such as shown in Fig. 17 may be employed wherein an instrumentl R in the form of a speed indicator .of known type or aninstrument especially made for obtaining the same effect may be used. This instrument may be v.con-

' nected to a Pitot and static pressure tube already existing on the machine or it may be connected to the Venturi tubeK8 which is connected to the mercury container K in order that the usual diaphragm therein may be moved by variations in the air pressure to movel'the indicating needle R in the well known manner. The indicating needle R" may be provided with a double contact R2 adapted to engaggJ with one or other of a pair of contacts 3, R3 adjustablymounted on the dial of the instrument. The contact R2 on the needle is connected by a conduct-or R4 to the mid-contact 11 in the mergage sary. to make the speed indicator'capable instrument dial are respectively connected by 4conductors R5, R6 to the'two .contacts 1,

lX of the mercury container-and to the conductors P, Px leading4 from therelays P, PX to the contacts 1, 1)c in the mercury tube. Should a changlg in speed take place, the speed'indicator being more sensitive than the mercury switch' is tirstbperated so that the 'needle R by means of its contact R2 engaging one or other of the contacts R2 closes a circuit through one or` other of the relays in order that the electro-magnets G2, G2X, H2, H2 may be energized and the aforesaid air controlling valves operated. Subsequently the mercury `column K will en-k or 1X in the tube K and the operation will then be controlled bythe movement of the mercury tube through the gear wheel M `and toothed sector M2 as in the modification shown in Figs. 12 to 15. It is necesi o dealing with different ranges of speed and it is for that reason that the contacts R3, R2 onthe dial are made adjustable so as to be moved nearer to or farther from the normal position of the needle by means of buttons operated by the pilot, the normal position ofthe needle It being the position which it would assume for'the normal or designed speed on the aircraft. In some cases the valves G, GX, H, HX instead of being moved by twelve volt electro-magnets as aforesaid may each be moved by air pressure which is controlled byv a small valve Q, operated by a two volt electro-magne,tl

Q, see Fig. .18. When the magnet Q `is energized by the mercury switch or the Pitot switch it moves the valve to allow air admitted through a pipe Q2 to flow through a pipe Q3 and move a valve G which controls'the air pressure. for operating the piston in the cylinder A according to any of the methods hereinbefore set forth.

In the modification shown in Figs. 19 to 22 which shows a motor or. contrivancethat can be used instead of theaforesaid piston motor a wind driven fan S suitably mounted to rotate when the aeroplane is flying, imparts rotation to gear wheels S, S2, S3, S4 in mesh as shown in Fig. 19 andso'arranged that the end wheels S2, S2 carrying friction wheels T, T- rotate in opposite directions. The several gear wheels are supported on a sliding frame S5 carrying at its ends armatures U, UX adapted to be attracted 'by electro-magnets U', UX to effect the sliding movement of the frame S5 so that one or other of the friction wheels yT or TX can with one or other ofthe contacts 1 J be moved into contact with a large wheel V takes place.

Fig. 17 as hereinbefore described when rela.-

tive movement between the mercury K and.- container K takes place. When one or other of the .electro-magnets U', UX is energized and the corresponding armature U or UX attracted, the sliding frame S5 is moved in order that one or other of the friction wheels T or T can rotate the large wheel V, the shaft V of which drives through worm 'gearing V2, V3 the shaft or spindle E which yis suitably connected to the aeroplane controls. This shaft E also carriesa tooth section M2k in mesh with a gear wheel M" vposition and means whereby the mercury column 'is placed under the inuence of wind suction control produced as a result.

of the flight ofthe aircraft to counteract the effect of centrifugal .force or inert1a on the mercury column which is thereby controlled to insure that the required relative displacement between it and the container 2. Apparatus fon use on aircraft comprising a mercury column in a container arranged in a 'transverse plane of the aircraft,

Venturi vtubes disposedv at extended posi-y tions one on-each sideof the aircraft body or fuselage with their axes in the direction of Hight, said VVenturi tubes being con.

nected by cross pipes to the ends of the mercury container whereby the mercury cana be controlled to enable relative movement between it and its container to take place.

3. Controlling or stabilizing apparatus for aircraft comprising a device containing .mercury under thev influence of wind suction control produced by the flight of the aeroplane, electrically operatedl means connected to the said device and the mercury and operated as a result of relative displace.

ment between the said device and the mercury, a cylinder containing a double-ended piston having a common rack rod in mesh with a gear segment connected to the aircraft controls, valves controlled by saidl electrical meansj/and associated with said cylinder, these 'valves controlling the vair pressure tothe cylinder to operate the pis-` ton and the aircraft controls through said rack rod `when the said valves are operated by, the electrical means on relative move* ment taking place between the said device and thel mercury.

4. Controlling orstabilizing apparatus `lcolumn is suctioncontrolled, electrical contacts in said mercury. container above the ends of the mercury column, a contact permanently in engagement with the mercury, electrical means operated as a result o-f rela.-

tve movement between the mercury column and its container insured by the suction control, apparatus, actuated by said electrical means in' order to operate the aircraft con- ,trols and means whereby the aircraft controls after being moved are caused to return to the normal position by reverse operation of said electrical means. Y

5. Apparatus for controlling an aeroplane in the transverse direction comprising a device containing a mercury column, the two ends of which are under the influence of wind suction control to counteract the effect of a centrifugal force by connections to Venturi tubes on the wing tips, electrical means connected to said device and the mercury and operated by the device moving Arelatively to the container when the aircraft banks or turns at which time the mercury is restrained against movement which tends to be produced by the action of centrifugal force, valves moving by the electrical. means which when operated allow air pressure at either end of a cylinder to move va piston connected to the aircraft controls by a member which in moving controls the electrical connections in a manner to cause the return movement of the piston to be effected.

6. Apparatus for controlling or stabilizing an aeroplane comprisin a mercury controlled switch under the in uence of suction produced by the flight of the aeroplane, which suction controls the mercury to insure relative displacementl between it and the mercury container and geared to a shaft which is connected to and adapted to be actuated to move the aircraft controls.

7. Apparatus for controlling or stabilizing aircraft comprising a mercury container, the ends of which are connected to means for enabling the mercury to be placed under ther influence of suction produced by the flight of the aircraft, twocontacts diametrically oppositein said container just above the ends of the mercurycolumn, a contact permanently in` engagement with the said mercury column and a toothed wheel connected to said mercury container and in mesh with a toothed segment on a shaft connected to the aircraft controls.

8. Apparatus for controlling or stabilizing aircraft comprising pneumatically operated means for moving the aircraft oontrols, electrical means'controlling the pneumatic means, a gravity switch controlled by wind suction control for controlling the said electrical means land a hand control valve fo'r rendering said pneumatic means operable or inoperable and an electrical switch controlled by said hand operated valve for controlling the electricalcircuits.

9. Apparatus for controlling or stabilizing aircraft comprisingifa semi-circular mercury column contained in a circular mercury container having two oppositely disposed contacts above the ends of the mercury column, a contact permanently in engagement with the mercury column and a toothed wheel carried by said container in mesh with a segment on a shaft which is I'connected to the aircraft controls and which carries a second toothed segment in mesh with a rack bar connecting two pistons in a cylinder whose ends can be placed in communication with an air supply for moving the piston in one direction or the other, the air supply being controlled by valves electrically operated as a result of relative displacement between the aforesaid mercury column and its container, which displacement is insured by placing the mercury under the influence of variatlons in suction produced by the flight of the aircraft.

l0. Controlling or stabilizing apparatus for aircraft comprising a mercury switch in which the mercury is under the influence of wind suction control, a Pitot tube, a preliminary switch operated by said Pitot tube and means whereby said preliminary switch is connected to the aforesaid mercury switch.

l1. Controlling or stabilizing apparatus for aircraft comprising a cylinder containing two pistons connected by a rod having a rack bar in engagement with a sector controlling the movement of a circular mercury container having a semi-circular mercury column, Venturi tubes connected to the ends of said mercury container above the ends of the semi-circular column, valves at the ends of said cylinder and electrical means associated with said valves and controlled by the relative movement between the'mercury and its container, which movement is insured by the effect of windpressure or suction produced by said Venturi tubes.

GEORGES AVELINE.. 

